1. Field of the Invention
The present invention relates to controlling a point-of-load regulator, or more particularly, to a system and method for using a serial bus to communicate with a point-of-load regulator.
2. Description of Related Art
Point-of-load (“POL”) regulators, which are also referred to as voltage regulators or DC/DC converters, are commonly used in conjunction with electronic circuits. This is because the voltage/current requirements of electronic circuits typically differ from the voltage that is readily available or the current that can practically be delivered. For example, some electronic devices only include a single voltage input (e.g., 12v), but require different voltages for circuits contained within (e.g., 3v, 5v, 9v, etc.). A common solution is to design multiple POL regulators within the device for converting the single input voltage into multiple voltage levels.
Similarly, some electronic devices include circuits that require low voltage (e.g., 1v), high current (e.g., 100A) power supplies. This is problematic in that it is impractical to deliver high current at low voltages over a relatively long distance and still meet desired regulation performances. A common solution is to use a high voltage, low current power supply and design a POL regulator near the internal circuit. This allows low current to travel throughout the device, and provides a low voltage, high current power supply (i.e., using the POL regulator) near the internal circuit.
Traditionally, POL regulators operate in conjunction with a power supply controller (“controller”) that activates, programs, and monitors the POL regulators. Specifically, the controller uses a multi-connection parallel bus (e.g., a six bit parallel bus) to activate and program each POL regulator. The parallel bus includes an enable/disable bit for turning the regulator on and off and VID code bits for programming the output voltage set-point of the regulator. The controller further uses additional connections (e.g., three wires) to monitor the voltage/current that is being delivered by each regulator.
The drawback with such a control system is that it adds complexity and size to the overall electronic device by using, for example, a six bit parallel bus to operate each POL regulator and three additional wires to monitor each POL regulator. In other words, a controller operating in accordance with this control system utilizes twenty-seven connections (i.e., twenty-seven wires or traces) in order to communicate with three POL regulators. Thus, it would be advantageous to have a system and method for communicating with POL regulators that overcomes these drawbacks.